It has long been known that the urinary bladder in the normal state is remarkably resistant to infection, although little has been described concerning any intrinsic antibacterial defense mechanism. A vesical mucosal bactericidal activity has been suggested, Cobbs, G. C. and D. Kaye (1967)., "Antibacterial mechanisms in the urinary bladder", Yale J. Biol. Med. 40:93-108; Cox, C. E., and F. Hinman, Jr. (1961), "Experiments with induced bacteriuria, vesical emptying and bacterial growth on the mechanism of bladder defense to infection", J. Urol. 86:739-748;and Norden, C. W., G. M. Green, and E. H. Kass, (1968), "Antibacterial mechanisms of the urinary bladder", J. Clin. Invest. 47:2689-2700, but its existence has not been corroborated by other investigators, Mulholland, S. G., E. A. Foster, A. J. Paquin, Jr., and J. Y. Gillenwater (1969), "The effect of rabbit vesical mucosa on bacterial growth", Invest. Urol. 6:593-604. It seemed unlikely that chance alone accounted for the bladder's ability to maintain a sterile lumen in the face of direct contact with environmental organisms; rather, antibacterial defense mechanisms might actively maintain this equilibrium. In this regard, I became interested in the concept of bacterial virulence depending on the ability of bacteria to adhere to a mucous surface.
Adherence has been postulated to play a role in bacterial virulence at many mucous surfaces including the gastrointestinal tract, the genitourinary tract, and the oral cavity, Ellen, R. P. and R. J. Gibbons (1972),"M protein-associated adherence of Streptococcus pyogenes to epithelial surfaces: prerequisite for virulence", Infect. Immuno. 5:826-830; Gibbons, R. J., and J. van Houte (1971), "Selective bacterial adherence to oral epithelial surfaces and its role as an ecological determinant", Infect. Immun. 3:567-573; Punsalong, A. P., Jr., and W. D. Sawyer (1973), "Role of pili in the virulence of Neisseria gonorrhoeae," Infect. Immun. 8:255-263; Sobelavsky. O., B. Prescott, and R. M. Chanock (1968), "Adsorption of Mycoplasma pneumoniae to neuraminic acid receptors of various cells and possible role in virulence", J. Bacteriol. 96:695-705; Svanborg-Eden, C., B. Eriksson, and L. A. Hanson (1977), "Adhesion of Escherichia coli to human uroepithelial cells in vitro", Infect. Immun. 18:767-774; Swanson, Jr. (1973), "Studies on gonococcus infection. IV. Pili: their role in attachment of gonococci to tissue culture cells", J. Exp. Med. 137:571-589; Swanson, Jr., G. King, and B. Zeligs (1975), "Studies on gonococcus infection. VIII. .sup.125 Iodine labeling of gonococci and studies on their in vitro interactions with eukaryotic cells", Infect. Immun. 11:453-459; Ward, M. E., and P. J. Watt (1972), "Adherence of Neisseria gonorrhoeae to urethral mucosal cells: an electron-microscopic study of human gonorrhea", J. Infect. Dis. 126:601-605; and Ward, M. E., P. J. Watt, and J. N. Robertson (1974), "The human fallopian tube: a laboratory model for gonococcal infection", J. Infect. Dis. 129:650-659.
The main theme of data obtained in these systems is that microbial ability to infect a surface is directly proportional to its ability to adhere to the mucosal cells. If adherence is important to bacterial virulence, it is possible that the body produces antiadherence factors as a counter measure. In the urinary bladder, an antiadherence factor preventing bacteria from adhering to the bladder wall would explain both the need for and the efficiency of the urine washout factor, Cox, C. E. and F. Hinman, Jr. (1961), "Experiments with induced bacteriuria, vesical emptying and bacterial growth on the mechanism of bladder defense to infection", J. Urol. 86:739-748. Human immonoglobulin A and glycoproteins have been studied as possible antiadherence factors acting in an antibody-like fashion, inactivating bacterial adherence mechanisms such as pili or the glycocalyx, Williams, R. C. and R. J. Gibbons (1972), "Inhibition of bacterial adherence by secretory immunoglobulin A: a mechanism of antigen disposal, "Science 177:697-699; Williams, R. C. and Gibbons, R. J.(1975), "Inhibition of streptococcal attachment to receptors on human buccal epithelia cells by antigenically similar salivary glycoproteins," Infect. Immuno. 11: 711-718. Such a mechanism would be less effective in the urinary bladder than at other mucous surfaces because it would require specific antibody production, which in turn requires prior exposure to antigens. Such a model does not adequately serve to explain the bladder's resistance to infection in the presence of a variety of environmental microorganisms.
Earlier investigations have shown that there is an interaction of microorganisms with mucosal surfaces as a prelude to infection on the surface of the bladder. Research efforts have shown that the ability of a bacterium to adhere to a mucous membrane is proportional to its virulence in the genitourinary tract, the gastrointestinal tract, and the oral cavity, Ellen, R. P. and R. J. Gibbons (1972), "M protein-associated adherence of Streptococcus pyrogenes to epithelial surfaces: prerequisite for virulence", Infect. Immuno. 5:826-830; Gibbons, R. J., and J. van Houte (1971), "Selective bacterial adherence to oral epithelial surfaces and its role as an ecological determinant", Infect. Immun. 3:567-573; Punsalang, A. P., Jr., and W. D. Sawyer (1973), "Role of pili in the virulence of Neisseria gonorrhoeae", Infect. Immuno. 8:255-263; Sobelavsky, O., B. Prescott, and R. M. Chanock (1968), "Adsorption of Mycoplasma pneumoniae to neuraminic acid receptors of various cells and possible role in virulence", J. Bacteriol. 96:695-705; Svanborg-Eden, C., B. Eriksson and L. A. Hanson (1977), "Adhesion of Escherichia coli" to human uroepithelial cells in vitro", Infect Immun. 18:767-774; Swanson, Jr. 1973), "Studies on gonococcus infection. IV. Pili: their role in attachment of gonococci to tissue culture cells", J. Exp. Med. 137:571-589. It appears that the host has immunodefenses or "antiadherence factors" directed against this bacterial virulence factor. The operation of such a factor at the surface of the transitioral epithelium in the urinary tract seems to explain the resistance of the bladder to infection.
I have previously developed an in vivo model to quantitatively measure bacterial adherence to the urinary bladder, Parsons, C. L., C. Greenspan, and S. G. Mulholland (1975), "The primary antibacterial defense mechanism of the bladder", Invest. Urol. 13:72-76. Data obtained using the model suggest that the transitional cells lining the bladder synthesize one or more glycosaminoglycans (GAGS) which appear to prevent bacterial adherence to the mucosal cells, Parsons, C. L., C. Greenspan, S. W. Moore, and S. G. Mulholland (1977), "Role of surface mucin in primary antibacterial defense of bladder", Urology 9:48-52. I call this substance, antiadherence factor.
My earlier experiments show that the layer of GAGs lining the bladder can be removed by acid treatment, with a corresponding rise in bacterial adherence, but that when heparin, an exogenous GAG is added to bladders rendered mucin deficient, bacterial adherence drops to control levels, Hanno, P. M., C. L. Parsons, S. H. Shrom, R. Fritz, and S. G. Mulholland (1978), "The protective effect of intravesical heparin in experimental bladder infection", J. Surg. Res. 25:324-329. Additional studies suggested that heparin coats the transitional cells at the bladder surface and acts as a barrier between the bacterium and the transitional cell, Parsons, C. L., S. G. Mulholland, and H. Anwar (1979) "Antibacterial activity of bladder surface mucin duplicated by exogeneous glycosaminoglycan (heparin)", Infect. Immun. 24:552-557.
One important consideration with regard to this latter finding was whether the anticoagulant effect of heparin was responsible for the antiadherence activity detected. I have now discovered that the antiadherence properties of an exogenous sulfonated semisynthetic analogue of heparin possessing far less anticoagulant activity than heparin has the capability of blocking bacterial adherence in vivo. Thus, it is now possible to control and prevent bladder infections by irrigation without exposure to unwanted anticoagulant activity.
I have also discovered that many disease states involve a decrease in the anti-adherence activity of the GAG layer, which I believe is the important interface between the transitional cells and all harmful substances in urine. Thus this invention is applicable even in cases where no bacteriological infection is involved. One such disease state may be interstitial cystitis, with urine as the pathogen and a defective GAG layer in the patient. Bladder tumors are another, whereby the GAG layer prevents carcinogens from adhering to the transitional cells and inducing a tumor (Parsons, C. L., Schmidt, J. D., and Pollen, J. J. (1982) "Successful treatment of interstitial cystitis with sodium pentosanpolysulfate", New Engl. J. Med., submitted for publication; Kaufman, J. E. and Parsons, C. L., (1982) "The effect of tryptophan metabolites and cyclamate on the bladder surface glycosaminoglycans: A mechanism for carcinogenesis", Cancer Res., submitted for publication; Bodenstab, W., Stauffer, C., Schmidt, J. D. and Parsons, C. L. (1982), "Protective effects of bladder surface glycosaminoglycans against carcinogenic agents", Poster Presentation Annual Meeting, American Urological Association, Kansas City, Mo., May 16-20, 1982.